i would only tell on a need to know basis.
it can sometimes come back to bite you in the butt.

i was a nurse and had a gait problem. i was going thru testing and couldn't keep it a secret. i told. initially i got a lot of support. but as i found it harder and harder to keep going physically my "friends" started to talk behind my back. i asked for some reasonable accommodations and got them but unbeknownst to me my coworkers felt they were given more work to take up the slack.

unfortunately (shame on them) my charge nurses weren't truthful with me.
but instead started documenting my problems. i'm sure had i not resigned they would have pushed me out. it would have been more honest for them to sit and talk to me. they took the sneaky and easy way out.

just remember that once you tell (as with anything) you can't take it back.
food for thought.